The NS 430 GPS navigation system, is an optional add-on module for most DCS World aircraft. It provides powerful, yet intuitive, navigation and radio communications options to supplement the navigation and radio systems already integrated into your aircraft. The NS 430 is particularly useful for older aircraft with less sophisticated navigation and communication systems.
This module provides ability to display the NS 430 as a pop-up window in almost all aircraft (except for those that have their own advanced navigation systems like the A-10C, Ka-50 and F/A-18C).
The NS 430 can also be separately purchased as an integrated cockpit panel option for DCS: Mi-8MTV2 and DCS: L-39 Albatros.
Source: The Game Website.